An electrical power generation apparatus may comprise an electrical generator that is driven by a turbine, for example. The electrical generator converts mechanical energy into electrical energy. A typical electrical generator includes a stator, and a rotor that rotates within the stator to generate electricity. The rotor is driven by a shaft to which it is mounted.
An isolated phase bus is commonly used to connect a step-up transformer to an electric generator. An example of such an isolated phase bus is disclosed in U.S. Pat. No. 2,548,566 to Stafford, for example. The isolated phase bus comprises a plurality of bus bars in an enclosure. The isolated phase bus connects an electrical generator to a plurality of transformers and is mounted to a plurality of H-beam supports by support rings.
U.S. Pat. No. 2,944,101 to Albright discloses a metal enclosed high voltage bus structure. The bus is suitable for supporting voltages of the order of 138 KV. The bus structure comprises flexible rolled sheet metal. To provide rigidity sufficient for mounting to supports, circular reinforcing members are fastened to the outside of the housing.
A problem associated with the above referenced configurations, however, is that they may require a large footprint, which may increase design costs, as well as overall plant costs. Further, the isolated phase bus may be cumbersome. Once the isolated phase bus is installed, maneuverability about the site may be difficult.
A product distributed by ABB under the commercial name of Powerformer™ is a high voltage generator using solid dielectric high voltage cables for stator windings. The high voltage cables can be connected directly to a transmission system. More specifically, the Powerformer™ uses underground cable technology (with Class A insulation, as understood by those skilled in the art) for stator windings. Low insulation temperatures, however, generally correspond to large size and/or low efficiency operation. Further, the Powerformer™ is generally custom designed for a given transmission voltage.